A network switch stores incoming network packets in a buffer memory and directs the stored packets to various output queues that share the buffer memory in the switch. The network switch preferably prevents any single output queue from taking more than its fair share of the shared buffer memory when the buffer is oversubscribed, but permits a single queue to take more than its fair share to handle incoming bursts if the buffer is not oversubscribed. Conventional buffer sharing techniques are overly simplistic in that they do not account for the fact that network packets may fall into multiple different traffic classes, such as voice, video, and data that may have different priorities and buffer storage needs. Also, the conventional buffer sharing techniques only apply to unicast traffic and thus ignore complications that arise from multicast traffic.